Inspection device for motion picture film



SePt- 12, 1933- E. T. FRANZEN i-T AL 1,926,521

' INSPECTION DEVICE FOR MOTION PICTURE FILM Filed Dec, 4l, 195o y/ j@ J9 m 6 @9 9 7 5 A i Z0 u INVENTORS ATTORNEY Patented Sept. 12, 1933 INsriioTloN DEVICE Fon MOTION Piernas Eric T1. Fra.nzen, Maplewood Township, Essex County, and ArthurV J. Weiss, West Orange, N. J., assignors to Franklin Williams, Inc., Orange, N. J., a corporation of New Jersey Application December 16,1930 Serial No. 502,706

s claims. (01. 177-311) This invention relates` to devices for inspect-,

ing motion picture films forV tears and breaks.

Heretofore, in the Vinspecting of motionpicture iilm for tears and breaks, it has been the practice for an operator to allow the film 4to pass between his fingers, the sensitivity of the fingers Ybeing relied upon to detect defects in the hn. Suchl a method is objectionable in that itis very taxing upon thengers ofthe operator', and

v too much reliance isV placed upon the sensitivity ofthe human element.

There are also automatic devices for detecting' breaks, such devices `usually comprising means for controlling a switch to discontinue the moving'of a film `upon the detection of a break.

However, the automatic devices are objectionable in that switch controlling mechanism is not reliable, requiring frequent and carefuladjustment, and the lm is not stopped instantly, necessitating in many cases that the nlm be unwound back from a reel to the section having the break.'

It is an object of this invention to provide an inspection device for -ilm by means lof which breaks are indicated audibly to an operator.

A further object is the provision of electrical means for indicating breaks in lms.

A further object is the provision of means for producing a sensible signal toindicate irregularities in surfaces required to be smooth.

A further object is the provision of means for producing an electrical current when a break occurs in a motion picture film being inspected.

These and other advantageous objects, which will later appear, are accomplished by the simple .35 and practical construction and arrangement of parts hereinafter described and `exhibited in the accompanying drawing, forming part hereof, and in which:

Figure 1 represents a plan view of the device. Y

` Figure 2 represents a side view of the device.

Figure 3 represents a sectional view of thedevice taken on line 3-3 of Figure 2.

Figure 4 represents a modiiied form of the in-v specting device in which a sensible signal is produced by variation in a column of gas or liquid. Figure 5 shows a further modification in which a signal is produced by varying the'iiow of current in an electrical circuitof the telephonetransmitter type. i

Referring to the drawing, the inspection vdevice is shown to include a plate 3 having a cover member 4 hinged thereto at 5. The plate 3 has spaced runways .6 and a central recess 7. Freely positioned in apertures in the runways 6 are .j plugs 8 having conical heads which project above and below the plate 3, and rest on a resilient cross bar 9 attachedito the stylus 10 of a magnetic unit 11 such'as a commonly used in sound reproducing devices. H

The stylus passes between the poles or arms of amagnet and througha small coil so that Vmovement `of the stylus will cause a current to be generated in the small coil 12 of the reproducing unit.

. Ear phones 13 may be attached to the termi- 65 nals 'of thecoil 12 or instead of the earphones, the coil may be connected to an amplifying device andthen to other signalling means, or to a light sensitive cell, or means for indicating movement ofjthe stylus's In operation,` amotion picture lm is passed over the plate 3, the edges of the nlm resting on the runways 6, and the recess 'l'preventing the frames oi the film from being scratched by contact with roughened surfaces as it passes through the inspection device.A

As long as there are no irregularities in the film, the pressure on the plugs is uniform and consequently there will be no movement of the stylus.

But, when anirregularity inthe nlm such as a break or patch passes over the plugs 8, the pressure is changed and the resilient cross bar 9 will be moved to move the stylus and cause a current to be generated in the coil 12.

VThe cross bar 9 is shown diagonally arranged l with reference to the runways 6. The purpose of this arrangement is to enable an operator to distinguish between a patch lin the lrn and a break'. When apatch occurs, the operator will 90 hear two sounds in succession in the ear phones; while with a break, only one sound will be heard.

While the device has been described as employing a magnetic unit, it is'obvious that other types 95 of reproducing units maybe used, such as the dynamic, electromagnetic and telephone transmitter types. Y.

In the modified form shown in Figure 4, the film passes over members similar to the plugs 8, which members arev in engagement with a re- V silient strip ,9u connected by a rod 10a to a diaphragm 14, covering a chamber 15, the latter being connected by va tube 16 to members 17 shaped for insertion in the ears. p 105 i Any disturbance of the strip 9a vwill cause aL similar disturbance of the diaphragm 14 and the gas or liquid column in the tube 16, and the disturbance will be readily noted by a person having the members 1'? in his earsin the same manner 1,10

2 as a physician employs a'stethoscope for inspecting the human body. t i In the modied form shown in Figure, a resilient strip 9b is connected bya rod 10b to a diaphragm l8 which engages carbon granules 19- in a circuit including a battery and ear phones 13b. The arrangement being similar to that of the Well known telephone transmitter.- l

Obviously, Whenever a break in a lm varies the pressure of the lm onvthe strip 9b, the disturbance will be transmitted to the carbon granules, and change the resistance of the circuit,

` and the current flowing therethrough, and. such n changes Will be readily indicated by the ear phones 13b.

From the above description, it will be seenY that Y Ihave provided eiective means for instantly indicating breaks in a film to an operator lby a sensible signal. The device includes-no resilient switch closing ngers Awhich become unreliable after being used for a While, nor is itk necessary to furnish electrical current for the device, as in the form shown in Figure 1, the eiect ofla break in a film is to produce a minute electrical current which is readily noted by the earphones. This same electrical current may be amplified and `serve as initial means for puttingrin operation devices to instantly stop movement of the film.

, Also, the device is not confined to the inspection of motion picture lm, but maybe employed in any situation Where it is'desired to detect irregularities in surfaces.

` The foregoing disclosure is to be regarded as descriptive and illustrative only, and not as restrictive or limitative of the invention, of which obviously an embodiment may be constructed including many modiiications without departing from the general 'scope herein indicated and denoted iny the appended claims.

, vHaving thus described our invention, what we claim as new and desire to secure by Letters Patent, is:

1..v In adevicefor detecting breaks in motion picture i-llm,y a plate having apertures, a pair of plugs over which the iilm passes, said plugs being in the 4apertures and projecting above and below the plate, a resilient bar bearing against the plugs below the plate, a stylus attached to the bar, and means associated with the stylus to produceva sound when a break in the film causes theplugs to bear unevenly on the bar.

2. Ina device for detecting breaks in motion picture lilm, a pair of spaced plugs over which the lm `passes, a resilient bar bearing against the plugs, and means connected -to thejbar to generate an electrical current when a break in the film causes the plugs to bear unevenly on thebar.Y

3. In a device for detecting breaks in motion picture film, a pair of spaced plugs'over which erate an electrical current When a break in the lm causes the plugs to bear unevenly on thebar.

ERIC T. FRANZEN. ARTHUR J. Weiss. 

